Mobile devices have included various types actuators to provide haptic feedback to a user. Haptic feedback is a method of providing a tactile response, through vibrations or other stimulation, to a user. Haptic feedback is helpful to a user because it can provide a simulation of a tactile sensation that emulates the response of an object represented in the user interface. Haptic feedback can also provide an indication to a user that an element has been selected, or a button has been pressed, a knob has been turned, or a slider has been moved, among other things, when the user is interfacing with a touch screen.
In devices with touchscreens, such touchscreens usually only sense the two-dimensional (x,y) location that is touched. A haptic feedback system that takes input from a two-dimensional touchscreen can provide a haptic feedback reaction to a touch in that location, but without a measurement of the z-axis force the haptic feedback system is not able to accurately emulate a response of an object represented in the user interface.
Some devices incorporate force sensors to measure the force of a touch on a screen. However, one problem with these devices is that the delay between the measurement of force and the actuation of haptic feedback is too long to provide an accurate emulation of the response of an object represented in the user interface.
Another problem is that the delay appears to the user to be a lag in the response of the user interface. For example, when typing quickly on a keyboard, lag in the haptic feedback of keypresses becomes readily apparent to a user.
Furthermore, where conventional devices simultaneously measure a location and force of a user input, a conventional processor cannot provide a custom haptic effect for that particular location or force level without the aforementioned lag.
A need therefore exists for a haptic feedback system that provides a haptic feedback response with a lower delay than conventional systems.